Hypothalamic-Pituitary

Acromegaly is characterized by excess GH secretion and insulin-like growth factor 1 (IGF-1) concentrations, most commonly due to a pituitary adenoma.

2.1.1.1 Prevalence and Incidence

Table 13 summarizes available data on the prevalence of acromegaly. No incidence data were available.

Note: * Prevalence estimates increased with age, ranging from 29-37 cases per million among children aged 0-17 years old to 148-182 cases per million among adults aged 65 years and older. Males and females were similarly affected; each with approximately 77 cases per million each year.

2.1.1.2 Cost Burden

The economic burden of acromegaly in the US is largely unknown. One study, however, examined the associated healthcare costs of acromegaly in the US from data from claims databases between 2002 and 2009 for 2,171 acromegaly patients. In this study, results indicated that acromegaly has a mean healthcare cost of $24,900 per patient per year, with medical costs accounting for $17,715, and $7,185 accounting for pharmacy costs. Importantly, medical costs were primarily associated with non-emergency department outpatient services ($12,268), and inpatient hospitalization ($5,213).⁷⁸

In addition, the presence of any complication statistically increased annual costs. In unadjusted comparisons to patients without complications, total costs were increased by $18,840 in patients with cardiovascular abnormalities, $16,701 in those with sleep apnea, $14,225 in those with colon neoplasms, %10,989 in those with musculoskeletal abnormalities, and $9,906 in those with hypopituitarism. Interestingly, costs were $2,610 lower in acromegaly patients with reproductive abnormalities than in those without. After adjusting for differences in age, gender, region, and cardiovascular risk factors, costs were increased by $8,401 in patients with colon polyps or colon cancer, by $7,502 in patients with musculoskeletal abnormalities, by $13,331 in those with cardiovascular abnormalities, by $10,453 in those with sleep apnea, and by $6,742 in those with hypopituitarism.⁷⁸

2.1.1.3 Life Expectancy and Mortality

Table 14 presents mortality data on patients with acromegaly.

Abbreviations: SMR, standardized mortality rate; n, number; US, United States; UK, United Kingdom.

2.1.1.4 Key Trends and Health Outcomes

 A recent study by Nachtigall et al. that included 100 patients at a neuroendocrine clinical center reported that primary care doctors play the major role in diagnosis of acromegaly, and that while 18% of patients present no symptoms at the time of diagnosis, acral changes (24%), and headaches (20%) are the most prevalent presenting symptoms prompting diagnosis.⁷⁹

Due to the variable nature of the disorder, an individualized treatment is necessary.  However, the Endocrine Society 2014 Clinical Practice Guideline for Acromegaly provides evidence-based recommendations for the evaluation and management of acromegaly, including an algorithm for an integrated multidisciplinary therapeutic approach.⁸⁰

Overall, the Endocrine Society Acromegaly Task Force suggests the following goals of management: 1) a biochemical target goal of an age-normalized serum IGF-1 value, 2) using a random GH < 1.0 ug/L as a therapeutic goal, and 3) maintaining the same GH and IGF-1 assay in the same patient throughout management.⁸⁰

In terms of treatment strategies, the Task Force recommends transsphenoidal surgery as the primary therapy in most patients. However, in patients with parasellar disease making total resection unlikely, surgical debulking is suggested to improve subsequent response to medical therapy. Finally, medical therapy is recommended for patients with persistent disease following surgery, while radiation therapy is suggested in cases of residual tumor mass following surgery, or in cases where medical therapy is unavailable, unsuccessful, or not tolerated. For more detailed information please refer to the Endocrine Society 2014 Clinical Practice Guideline for Acromegaly.⁸⁰

Recently, Broder et al. reported that out of 2,171 acromegaly patients, 77.8% received the majority of their care from non-endocrinologists, and 30.8% used pharmacologic treatment.⁷⁸ Table 15 summarizes the monitoring tests and treatments used by these patients during the 12-month study period.

Source: Broder et al. 2014⁷⁸

In terms of complications related to acromegaly, the most common are musculoskeletal abnormalities (25.6%), hypopituitarism (16.6%), sleep apnea (11.5%), cardiovascular abnormalities (10.3%), reproductive system abnormalities (9.3%), and colon neoplasms (6.6%). In addition, cardiovascular risk factors have been reported in 47.6% of patients: hypertension (31%), hypertriglyceridemia (19.8%), and diabetes (17.5%). When conducting unadjusted comparisons, inpatient hospitalizations increased in patients presenting any complication, except in the case of reproductive abnormalities, which were related to a decrease in hospitalization. Similarly, in comparison to patients without complications, emergency department visits were more common in patients with cardiovascular disease, musculoskeletal conditions, and hypopituitarism. After adjusting for differences in age, gender, region, and cardiovascular risk factors, musculoskeletal abnormalities increased the odds of hospitalization (odds ratio [OR]: 1.76), as did cardiovascular abnormalities (OR: 2.93), and sleep apnea (OR: 1.56). Further, the odds of an emergency department visit increased with musculoskeletal (OR: 1.87), and cardiovascular abnormalities (OR: 2.32).⁷⁸